GPS monarch butterflies on antennas

2009/10/01 Lakar Iraizoz, Oihane - Elhuyar Zientzia

• Zoologia

The antennas allow monarch butterflies not to lose the orientation they should follow during their migration, according to a group of neurobiologists from the University of Massachusetts.

Scientists have long known that they use the position of the Sun to know where these butterflies have to go. In fact, they have a kind of clock that adapts throughout the day so that the movement of the Sun does not affect orientation.

So far it was thought that this clock was in the brain, like the clock that regulates cycles throughout the day, or circadian cycles. However, Massachusetts scientists have experimentally demonstrated that not in the brain do they have the system on the antennas to determine the course of the journey.

The experiments carried out consisted, in the first place, of cutting antennas to butterflies and studying their behavior. They saw that they lost all the orientation and took the randomly chosen directions to fly.

Later, instead of cutting them, they painted the antennas with enamels: some with opaque black enamels and others with clear enamels. Thus, the researchers considered that the clock that followed the movement of the Sun in the antennas would only lose the orientation capacity of the butterflies that had antennas painted black. And so it happened.

Images: Big, Monarch Watch-Chip Taylor, small, Dennis Curtin